Milleropsis

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Wikipedia

Milleropsis
Temporal range: Late Permian, Changhsingian
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Reconstructed skull of Milleropsis based on micro-CT scans
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Subclass: †Parareptilia
Order: †Millerosauria
Family: †Millerettidae
Genus: †Milleropsis
Gow, 1972
Type species
†Milleropsis pricei
(Watson, 1957 [originally Millerosaurus pricei])
Synonyms

Millerinoides Broom, 1941
Millerinoides acutirostris Broom, 1941

Milleropsis is an extinct genus of millerettid reptile from the Late Permian (Changhsingian stage) of South Africa.[1][2][3] The holotype specimen of Milleropsis (BP-1-720) is a preserved burrow aggregation of at least nine semi-articulated individuals.[4] Recent work using high-resolution CT imaging has demonstrated that Milleropsis shares a variety of anatomical features with neodiapsid stem reptiles, casting doubt on the validity of Parareptilia, the clade to which millerettids have often been assigned.[5][6]

Research by Jenkins and colleagues (2025) based on synchrotron data and an expansive phylogenetic dataset recovered the Millerettidae as the sister group to the Neodiapsida, close to the reptile crown group. Milleropsis was recovered as the sister taxon to the clade formed by Milleretta and Millerosaurus. These results are displayed in the cladogram below, with taxa traditionally regarded as 'parareptiles' highlighted:[6]

Sauropsida

   former 'parareptiles'

References

  1. ↑ Gow, C. E. (1972). "The osteology and relationships of the Millerettidae (Reptilia: Cotylosauria)". Journal of Zoology. 167 (2): 219–264. doi:10.1111/j.1469-7998.1972.tb01731.x. ISSN 1469-7998.
  2. ↑ Cisneros, Juan Carlos; Rubidge, Bruce S.; Mason, Richard; Dube, Charlton (24 November 2008). "Analysis of millerettid parareptile relationships in the light of new material of Broomia perplexa Watson, 1914, from the Permian of South Africa". Journal of Systematic Palaeontology. 6 (4): 453–462. doi:10.1017/S147720190800254X. ISSN 1477-2019. S2CID 73723455.
  3. ↑ Marcello Ruta; Juan C. Cisneros; Torsten Liebrect; Linda A. Tsuji; Johannes Muller (2011). "Amniotes through major biological crises: faunal turnover among Parareptiles and the end-Permian mass extinction". Palaeontology. 54 (5): 1117–1137. doi:10.1111/j.1475-4983.2011.01051.x.
  4. ↑ Watson, David Meredith Seares (January 1997). "On Millerosaurus and the early history of the sauropsid reptiles". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 240 (673): 325–398. doi:10.1098/rstb.1957.0003.
  5. ↑ Jenkins, Xavier A.; Benson, Roger B. J.; Ford, David P.; Browning, Claire; Fernandez, Vincent; Griffiths, Elizabeth; Choiniere, Jonah; Peecook, Brandon R. (2025-01-08). "Cranial osteology and neuroanatomy of the late Permian reptile Milleropsis pricei and implications for early reptile evolution". Royal Society Open Science. 12 (1) 241298. doi:10.1098/rsos.241298. PMC 11707879.
  6. 1 2 Jenkins, Xavier A; Benson, Roger BJ; Ford, David P; Browning, Claire; Fernandez, Vincent; Dollman, Kathleen; Gomes, Timothy; Griffiths, Elizabeth; Choiniere, Jonah N; Peecook, Brandon R (2025-08-28). "Evolutionary assembly of crown reptile anatomy clarified by late Paleozoic relatives of Neodiapsida". Peer Community Journal. 5. e89. doi:10.24072/pcjournal.620. ISSN 2804-3871.